Form tool grinding attachment for grinding machines



1949- w. J. CHRISTIANSEN FORM TOOL GRINDING ATTACHMENT FOR GRINDING MACHINES Filed Aprll 15 1948 Patented Jan. 4, 1949 UNITED STATES TE roFF-ict:

FORIWI TOOL GRINDING ATTACHMENT FOR GRINDING MACHINES William Joseph Christiansen, Bogota, N. J.

Application April 15, 1948, Serial No. 21,163

Claims. 1

The object of this invention is to provide a novel and improved form tool grinding attachment for grinding machines. The attachment is an article of manufacture, that is, it is a complete unit comprising a tool resting plate with guiding edge, a tool form block with a tool post to support the tool to be ground. The form block is a special feature of the invention because by setting the tool in a selected position on the block the tool may be automatically ground with predetermined angles or a predetermined shape determined by the angles or shape of the tool block. The attachment incudes clamps for securing it to a standard grinding machine and adjusting means for placing the tool in the proper operative relation to the grinding wheel. In the accompanying drawing:

Fig. 1 is a perspective view of a grinding attachment embodying the invention.

Fig. 2 is a plan view with parts broken away.

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2 and shows how the attachment is secured to the grinding machine.

Fig. 4 is a detail rear view of the supporting bracket and the tool resting plate and illustrate parts of the tool adjusting mechanism. a

Fig. 5 is a view showing the attachment mounted on a standard grinding machine, only one half of the machine being shown.

Figs. 6 and 7 are detail views illustrating some of the uses of the invention.

Referring to Figs. 1-3, the stock or tool In to be round is removably clamped in a tool post II by a screw l2. The post H is rotatably carried by the tool form block I3 in a circular recess [4 having an undercut recess to receive a circular flange it On the post. When the tool I0 is inserted through an opening I! in the post and the screw i2 is screwed down, the tool is clamped" against the top surface 18 of the block.

The form block [3 is preferably a triangular piece having three distinct angular corners. For example, the angles at the corners of the block may have, respectively, angles of sixty, forty-five and twenty-nine degrees, these being the most wanted angles of the tool. However, the angles are not critical, neither need the corners be pointed.

In Fig. 2 the grinding angle at A is sixty degrees so that the tool ID will be ground with a sixty degree angle, the point 20 having sides 2| which form such an angle. The tool angle will be formed automatically by clamping the tool in the post and then move the block l3 along the guiding edge of the tool resting plate 24. The

will be above the selected corner of the bloclc.

The sides 22 and 23 of the block constitute tool forming sides in that, as the block is moved manually on the plate 24 with the side 23 in constant sliding contact with the guiding edge 25, the one side 2| of the tool will be ground parallel with the block side 23. When the block is turned so that its other side 22 engages the edge 25, the other side 2| of the tool will be ground in the same manner. Inasmuch as the sides 22 and 23 form an angle of sixty degrees the tool will be ground with the same angle. It will be noted that by merely selecting one of the angles on the tool block the tool will be ground with the same angle.

The tool rest plate 24 is adjustably and slidably carried in a supporting bracket 34 having two clamps 26 with screws 21 to clamp the bracket to the standard tool rest 28 on a grinding machine 30, The plate 24 has grooves 35. has flanges 36 which slide in the grooves.

threaded engagement with a rotatable bearing 33 in the bracket. When the screw is operated, the plate 24 is caused to move in the bracket towards or away from the grinding wheel 29. Inasmuch as the bearing 33 is rotatable in the bracket it is immaterial whether the plate is placed parallel with the grinding surface of the wheel.

The clamps 28 on the bracket are spaced apart to fit the standard tool rest. Inasmuch as thev grinding machine usually include a coarse and a fine grinding wheel, the bracket will fit right or left on the machine. In Fig. 5 only one wheel is shown and the right hand clamp 26 is not screwed fast on the machine tool rest. Only one half of the machine is shown, the other half being identical in construction.

It is not critical that the attachment be mounted on the machine in precise relation to the direction of the grinding surface of the wheel or parallel to the wheel shaft 50. As seen in Fig. 6 the plate may be positioned without such exactness without affecting the grinding operation.

In use, the tool form block will be moved along the guiding edge 25. First with one side 23, then with the other side 22 in contact with the edge. The left hand view in Fig. 7 shows the form block in the latter position. In addition it shows a block having a round corner at 40. The right hand view in Fig. 7 shows how the tool is ground with a round corner 45 as a result of the grinding operation. The round shape is obtained by keeping the round corner of the block in constant The bracketv The plate carries an adjusting screw 32 which is in;

the distance between the tool and the grinding The result will be that the tool will be' 4 the attachment to the grinding machine with the clamped tool in operative grinding relation to said grinding element.

3. A form tool grinding attachment for grinding machines having a tool grinding element, said attachment comprising a tool rest plate having a tool guiding edge, a tool form block having two adjoining sides forming a selected angle and resting upon said tool rest plate in movable relation thereupon, a rotatable tool post in said block, a screw in said post for clamping a tool I to the block with the longitudinal axis of the tool bisecting the said angle, said tool block being adapted to be moved manually upon said rest said, guiding edge to cause the clamped tool to tachment for a grinding machine, the latter in-" eluding a tool rest and a grinding wheel, said attachment comprising a tool rest plate having a tool guiding edge, a tool form block having at leastone corner forming a predetermined angle between two adjoining sides of the block, means for clamping a tool to said block in a predetermined grinding position with respect to the said one angular corner, said tool form block being manually movable upon the said tool rest plate along the guiding edge thereon with the tool extending from said block into grinding relation with .the said grinding wheel to be automatically ground thereby with an angle similar to the said angle of the block as the latter is moved along the said guiding edge. with the said adjoining sides in alternate engagement with the edge and means. for mounting the attachment upon the tool. rest of the grinding machine in operative relation to said grinding wheel.

2. A tool grinding attachment for grinding machines having a tool grinding element, said attachment comprising a tool rest plate having a tool guiding edge, a tool form block having two adjoining side s forming an angle and resting with the said adjoining sides of the block in ;alternate engagement with the said guiding edge to cause, the clamped tool to be ground with an angular point forming an angle equal to the angle aforesaid and clamping means for securing be ground with a like selected angle and clamping means in the attachment for securing the same to the grinding machine with the clamped tool in operativegrinding relation with said grinding element.

4. Atool form grinding attachment according to claim :3 including a bracket for clamping the attachment to the grinding machine, grooves formed, in the bracket, flanges formed on said tool restplate slidably supported in said grooves, a bearing pivoted in said bracket and a screw in threaded engagement with the bearing and supported in said rest plate for adjusting the plate with respect to thebracket and the grinding element in the grinding machine.

5. As a new article of manufacture, a form tool grinding attachment for grinding machines comprising a bracket forming clamps, screws in the clamps for securing the bracket to a grinding machine tool rest, a tool rest plate movably supported in the bracket, said plate having a tool guiding edge, a tool form block having at least one corner of a predetermined angular formation, a tool post in said block for clamping a tool to theblock, the latter being adapted to be moved manually upon the said tool rest plate with the adjoining sides of the said corner in alternate engagement with and along the said guiding edge for causing the clamped tool to be ground with a like predetermined angular formation and means for adjusting the said tool rest plate upon the said bracketvto adjust the operative relation of the clamped tool with a tool grinding element.

WILLIAM JOSEPH CHRISTIAN'SEN.

No references cited. 

